There are no recent reports of maintenance from EA about this on their blog or the EA Tapped Out blog (as of 8:30pm GMT), so lets hope this is just a quick fix, not a closure of the iOS game!
-Day
UPDATE: This was a short outage from about 2pm GMT to 8:30pm.

So, really I’m not going in on the details of the first 9 levels of what happens in STO (Simpsons™ : Tapped Out) because it’s boring. I will be showing pictures of major events and talkin’ about them.
Enjoy!
DayStar